A typical web application consists of a number of elements arranged hierarchically or in another manner to facilitate rendering by a web browser application running on a client device. The web application can be written in hypertext markup language (HTML) or another suitable markup language that the browser is configured to render, including tags and other content defining or corresponding with elements of the web application. Further or alternatively, aspects of the web application can be defined dynamically using JavaScript or other scripting languages. For instance, a set of JavaScript code could be written to dynamically define the general structure or shell of a web application and to then use context (such as stored user information or user input) to obtain or build other elements of the web application. A web browser could obtain the JavaScript code from local storage or by request from a server (e.g., by an application programming interface (API) call) and, in accordance with the code, could render the web application.
In addition, the JavaScript code or other logic underlying a web application could define various subscriptions or other mechanisms to facilitate dynamic updating of web application content such as particular elements or groups of elements. These subscriptions could implement a subscribe-publish protocol and a persistent connection (e.g., open web socket) between the web browser and a server, with browser sending a subscription query to the server and the server establishing a mapping of the subscription to particular channels, data records, or other content and being configured to push updates to the browser. When the server detects content updates (e.g., when a data record is changed), the server could thus transmit the updated content to the web browser. And when the browser receives the updated content, the browser could accordingly re-render or otherwise update the web application.